class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        ListNode* cur1=l1,*cur2=l2;
        ListNode* newhead =new ListNode(0);
        ListNode* prev=newhead;
        int t =0;
        while(cur1||cur2||t)
        {
            if(cur1)
            {
                t+=cur1->val;
                cur1=cur1->next;
            }
            if(cur2)
            {
                t+=cur2->val;
                cur2=cur2->next;
            }
            prev->next = new ListNode(t%10);
            prev=prev->next;
            t/=10;
        }
        prev = newhead->next;
        delete newhead;
        return prev;
    }
};